Textile treating compounds



Patented Aug. 19, 1952 TEXTILE TREATING COMPOUNDS William L. Dills,Wilmington, Del., assignor to E. I. du Pont de Nemours & Company,Wilmington, DeL, a corporation of Delaware No Drawing. Application June24, 1950,

Serial No. 170,265

8 Claims.

This invention relates to novel titanium-antimony compositions useful intreating organic substances, especially textile materials, in order toimpart valuable properties thereto. More particularly it relates to theproduction and use of a novel composition comprising titanium andantimony, useful for rendering textile materials flame-resistant.

The various textiles, such as rayon and cotton goods, present anappreciable fire hazard due to the ease with which they may be ignited.This is particularly true in clothing such as lightweight rayon dressgoods or in heavier fabrics having a pile finish. The finer pile fabricsare often made by brushing regenerated cellulosic textiles, e. g., wovenor knitted viscose goods, and these are particularly hazardous due tothe ease with which a flame may spread over the pile material. Thedangers have been brought to the attention of the public by the manydisasters in recent years resulting from the increased use of fabricshaving such high susceptibility to flamepropagation. ActiOn has beentaken by the American Association of Textile Chemists and Colorists,which has developed a testing method to' determine the flashorflame-resistance-of textile fabrics. In such a test a rectangle oftreated cloth measuring 2" x 6" must be heated for fifteen minutes at105 C. and then cooled in a desiccator over calcium chloride. Theresulting dried cloth will have a moisture content of less than 0.3under such conditions. The cooled cloth must then be removed from thedesiccator, supported on a screen held at a 45 angle, and touched with a/2" flame for one second. To pass the test, pile goods must not showmaterial flashing, even after laundering. Flat or non-pile goods may betested similarly, but the flame in this instance is applied to goodssuspended in a vertical position, and the goods must not continue toburn after the flame is removed.

Various compounds have been added to, or incorporated in fabrics toattempt to render them fireor fiameproof. The most widely employedprocess comprises coating the textile simultaneously with a chlorinatedresin or chlorinated paraffin and an inorganic oxidic material. Suchcompositions have been used especially to render tarpaulin tentingmaterial fiameproofand for like military applications. Such a method,however, substantially changes the character of the goods because thecoating is of substantial thickness and the textile loses itsflexibility. Too, although the coating is relatively water-resistant andthus durable to laundering, it is not resistant to the solvents used indry-cleaning but is dissolved thereby. Hence, fabrics so treated are notsatisfactory for general clothing purposes and are not even acceptablefor work clothing. In addition, it has been suggested that fabrics betreated with an inorganic salt such as a chloride of titanium, tin orantimony, dissolved either in water or in non-aqueous solvents liketoluene, ethyl acetate, etc. Fabrics have also been contacted withammonium sulfamate, alone or in conjunction with soluble salts, e. g.,borates and the like. However, none of these prior art processes hasgiven products which at the same time meet the above-referred-to AATCCtest for flashor flame-resistance, are dry-cleaningandlaundering-resistant and give a product having consumer appeal.

More recently it has been proposed to apply a combined solution ofantimony and titanium to textile materials; such a method is outlinedand claimed in co-pending application Serial No. 724,242, filed January24, 1947 by F. W. Lane and myself, which has issued as U. S. Patent No.2,570,566, dated October 9, 1951. The fabric is immersed in theantimony-titanium solution; after a short lag period, the fabric istreated with an alkaline neutralizing agent, such as ammonium hydroxideor sodium carbonate, and then rinsed or washed to remove anyloosely-held inorganic oxides and salts. Upon drying, it is ready foruse as a flame-resistant textile. This method has shown great promise,since it provides clothing, drapery, curtain, and industrial fabrics ofgreater consumer appeal, and having a flameresistance which is durableboth to laundering and to dry-cleaning. Most important, of course, isthe fact that it makes economically possible the obtention of clothingmaterial which passes the rigid AATCC fire-resistance test andimplements practically the enforcement of fire prevention laws such asthat enacted in California.

It is among the objects of this invention to substantially improve uponthe operations recited in the above-mentioned Lane and Dills applicationand to provide the textile trade with a flameretarding compositioncomprisin titanium and antimony in more concentrated form. Anotherobject is to provide a composition which is soluble in an aqueous mediumbut which may exist as a solid or powdery material and be transported inrelatively inexpensive containers. A further object is to provide to thetextile-finishing industry an anhydrous reagent which may be transportedfrom its point of manufacture to the consumer at decreased shippingcharges. Other obchloride of antimony, e. g., SbCls, as may beillustrated in part by the hypothetical equation:

3TiCl4+Sb2O3- 3TiOCl2+2SbCl3 This reaction takes place with thegenerationol heat. The product is dry, and will be substantially devoidof visible fumes when there is no excess of anhydrous TiCh therein. Inthe event that one uses an excess of titanium tetrachloride, a fumingsubstance results which may be used as such, if suitable packaging andother precautions are taken. However, if it is desired to eliminate thefumes, this may readily be done by the addi- Y tion of sufficient waterto convert the excess TiCli to an oxychloride, e. g.

In a preferred embodiment of my invention, I react titaniumtetrachloride with antimony oxide, using approximately three mols .ofTiCh for each mol of SbzOc in accordance with the first equation givenabove. This ratio :of

titanium to antimony has been found quite satisfactory in theflameproofing of fabrics, particularly cellulosic fabrics made of rayonand cot ton yarns. The product has been found quite soluble in water orwater containing an acid such as hydrochloric, acetic, chloracetic orother similar reagents useful in maintainingtitanium and antimonychlorides in solution in a dilute aqueous medium.

When one stirs antimony oxidev into titanium tetrachloride, spontaneousreaction may or may not. take place, depending on the purity of thereagents and their freedom from moisture as well as the temperature ofthe suspension. I find it convenient to mix the two reagents underconditions which will give a uni-formcomposition prior to the beginningof the reaction. In other words, I prefer .to mix the two in the absenceof water and while keeping the temperature low, and then initiate the,reaction by adding. a trace of water. catalytic in its behaviour; or itis also possible that the water-addition generates heat and raises thetemperature to the point where the reaction itself starts and spreads.

My method of preparing these solid flame-retarding compositions issubject to considerable variation without departing from the spirit ofthe invention The product may vary in composition over a considerablerange without becoming liquid or even tacky. A free-flowing powderhaving a variable ratio of titanium to antimony is therefore possible,depending on the amount of each ingredient employed. The. use of amountsof titanium tetrachloride in excess of that shown inv thehereinbefore-mentioned equation, e. g.,'four mols of TiCli for each molof SbzOc, will result in a reaction product contai'ni'ng residual'IiCli. Upon subsidence of the reaction and exposure of the mass toth'emoist atmosphere, a funding product'is thus obtained. However, ifdesired, this visible smoke or fume may be avoided by adding to thereaction mass a limited amount of water so as to convert the residualtetrachloride to an oxychloride suchas TiOCl'z. This use of a quantityof water The latter may be stoichiometrically equivalent to the excessTiCll present should not be confused with the utilization of a small ortrace amount to catalyze or accelerate reaction between the titaniumchloride and antimony oxide as above disclosed. The product resultingafter the addition of water to react with an excess of one mol of TiCl4will contain approximately two atoms of titanium per atom of antimonyand will be a dry powder which is free of visible fumes and which may betransported like other powders in simple drums or bags.

The solid fiameproofing product of this invention may also be modifiedby using a larger proportion of antimony oxide, in which event theantimony content will be greater than that provided by the previouslymentioned reaction For instance, equimolar proportions of the reactantsmay be employed, according to the equation The antimony will be presenteither as unconverted oxide, as the normal chloride or as a basicchloride, depending on the conditions of reaction between the titaniumtetrachloride and theantimony reagent. Such a product will dissolve indilute acid, e. g., 20% HCl, to give a clear solution which may be useddirectly in the treatment of inflammable textile fabrics, or maybefurther diluted with water or modified in other ways depending on thewishes of the consumer.

To a clearer understanding of my invention, the following specificexamples are given, it being understood that they are merelyillustrative and are not to be taken as limiting the scope of myinvention:

Example 1 One hundred parts by Weight of antimony oxide were slurried in190 parts by weight of anhydrous titanium tetrachloride and after auniform suspension was obtained, water was added in a dropwise manneruntil reaction set in. Heat was generated and fumes appeared above thereacting mixture. After the initial reaction had subsided, 18 parts byweight of water were slowly added with agitation to the solid reactionproduct. Fuming ceased and the final'prodnot was a dry, powderymaterial.

This dry mixture of titanium and antimony chlorides was found todissolve readily in water acidulated with 20 HCl, and a veryconcentrated solution could be thus prepared. A por-' a 15 minute lagperiod,'imme'r'sed in a saturated The fabric wasfinally thoroughlyscrubbed with soapy water,

sodium carbonate solution.

rinsed, dried; and a portion tested by the AATCC test "(dried in aproper desiccator, supported at a 45 angle and touched for 1 second witha -inch flame). No flashing occurred on the pile surface. Anotherportion of the treated material was subjected. to chemical analysis andfound to contain 7.5% 'I'iOa and 7.0% SbzOa;

gem-#29 wer jslurifiediin 205 "parts "weight of Ti C li whileithelatterwas being stirred and'maintain'ed at, allow" temperature by, waterjacket cooling. N'o" reaction" took place during the mixing, but when auniform suspension was obtained, water was added dropwise toira'ise; thetemperature and initiatethe'reaction. Dense fumes were evolvedin'the-moist'air andthe reaction'was vigorous, continuing for about '15'minutes. Twenty eight parts-byweightof water were then added dropwisewith stirring, converting the excess of TiCl4 to an oxychloride, inwhich condition it became substantially non-fuming. Stirring wascontinued until the mixture was ,free of any lumps, and the sqlidproductwasthentested for solubility. It wasfou'nd to leaveSomeih's'olubleresidue when treated with HC1 but to dissolvecompletelyin 'I-ICl. --The solid analy zed 25.9% TiO2,33.6% SbzOs, and42.1% H01;

The product of this example, like that of-Example'I,-was=found to bea-valuable fiameproofing compound for rendering inflammable textilematerialssuch as rayon and cotton goods fireresistant. v r l As,disclosedaboveand illustrated in theexample's, I have outlined amethodfor'producing solidcompositions useful in the treatment 'jof textiles toreduce fire hazards. soluble-Yin water or acidulated Water or the like,e. "g'.,' a 10% or 20% HCl solution, solutionsof sulfuric acid, aceticor chloracetic acids, propionic acid, other water-soluble acids, etc.The exact chemistry of the reaction between antimony oxide and titaniumtetrachloride is unknown but is believed to follow one or more of thefollowing equations:

One may observe that the process is flexible in that a considerablevariation in the ratio between antimony and titanium is possible and thereaction yields a mixture of a chloride and one or more oxychlorides.For reasons of simplicity, I use the term chloride to include both thenormal chloride and the oxychloride or basic chloride, as for exampleTiOC12 or SbOCl, and it is understood that the extent of the reactionbetween the two reagents and the chemical composition of the reactionproducts is not a fundamental of my invention. I regard my invention asa means of preparing a solid material which will readily dissolve in anaqueous system and which is useful as a treating agent for inflamabletextile goods to render them fire-resistant. A close examination of theequations given above will show that it is possible to produce solidcompositions comprising chlorides of titanium and antimony in which theratio of antimony to titanium may be as great as two and as low asone-half.

In the examples, I have shown the reaction taking place in the absenceof a diluent or solvent. It is naturally essential to avoid contact witha substantial amount of water in order to produce a dry, powderymaterial; but excess TiCl-i may be consumed by reaction with anequivalent amount of H20. The reaction may be aided and accelerated bythe application of a small amount of heat. Additionally, the processThese solids are a can be. carried out. the-presence of.anonganicsolvent such as benzene, toluene, or cycle hexane, and it.should vbeunderstood. thati'such a modification .comes within. the'scopeofathis in vention. The '.:.avoidance of "such additional reagents:is-generally recommended, however; for economy .as well as forminimizing operational complications. y ..'.r:::.:-;

The solid,'.soluble concentrates of thisinvention form aqueous.solutions which. are. particularly effective. for treatingfilamentstmdfilms comprising fmaterials which reactchemically with them"toimpart tov suchfilaments and filmsdesired name-resistancecharacteristics. Thus, while after-treatment of .polyacrylom'trile yarnwith these flame-proofing. compositions is relatively ineffective,excellent results; .are. ob.- tained by after-treatment ofacrylonitrilelpoly mers containing reactive functional groups, such as.hydroxyl groups, carboxylgroups, and groups which hydrolyze tothe'seunder the after-treat-- menti..conditions;.. v :Someofthe moresuccessful methods of modi-. fying polyacrylonitrile so that filmsandpfilaments. can be, flame-proofed; with .the compositions. of. thisinvention are: -(-1) partial hydrolysis to provide amide or carboxylic:groups, (2) .:use of acrylonitrile, 'co-polymer ...containingc, "suchgroups as hydroxyLcarboxyl, -anhydrides, amides, lactones,,esters, andamines,--andl(3) incorpora-r 'tionofmaterials containing such groups as,thfise into fibers by impregnation or by inclusionin the spinningcompositions. Many of, these techniques are applicable to other fibers,and particularly the third treatment could be applied to any syntheticfiber.

I claim as my invention '1. A solid dry aqueous-media-solublecomposition for rendering inflammable textile materials flame-resistantwhich consists in a reaction mixture of titanium oxychloride with acompound of antimony selected from the group consisting of a basic andnormal chloride, the atom ratio of antimony to titanium in saidcomposition being not more than two and not less than one-half.

2. Dry, powdery flame-retarding composition, useful for the treatment ofinflammable textile materials and soluble in an aqueous system, whichconsists in titanium oxychloride and antimony chloride, the atom ratioof antimony to titanium in said composition being not more than two andnot less than one-half.

3. A process for the preparation of a soluble. solid flame-retardingcomposition of matter which comprises mixing in the dry state, antimonyoxide with titanium tetrachloride, incorporating a small amount of watertherein, and thereby converting the tetrachloride to an oxychloride andthe antimony oxide to a chloride, and employin therein such ratio ofreactants that the resulting composition contains an atom ratio ofantimony to titanium of not more than 2 and not less than one-half.

4. A process for the preparation of solid flameretarding compositions ofmatter soluble in aqueous media, which comprises mixing in the dry stateantimony oxide with titanium tetrachloride, and adding a small quantityof water thereto, the amount of the reagents being so selected that theproduct will comprise .an oxychloride of titamum and a normal chlorideof antimony, with its atom ratio of antimony to titanium being not morethan 2 and not less than one-half.

5. A process for the production of a solid, flameretarding reagentcomprising chlorides of titanium. and antimonyso'lub'le. in aqueousmedia which comprises mixing together inthe .dry state antimony oxideand titanium tetrachloride. .adding enough water to the mixture toconvert any unreaoted titanium tetrachloride :to titanium oxychioride,and employing said reactants insuch proportion that th'esolid productobtained will contain an atom ratio of antimony to titanium of .not:more than 2 and not less than one-half. 5.6; A process for theproduction of .the solid flamzeretarding reagent: comprising an.oxychlorideoftitanium' and antimony chloride soluble in aqueous mediawhich comprises mixing together in: fthedry state for reaction antimonyoxide and titanium tetrachloride, employing an atom ratio of antimony totitanium in the reaction mixture of :notimore than two norless thanone-half, and theniniti-ating areaction between the compounds admixed byadding water .dropwise thereto.

7. A process for the production of a solid flameretarding reagentcomprising an oxychloride of titanium and antimony trichloride' solublein aqueous media which comprises reactingttogether antimony trioxide andtitanium tetrachloride by mixing said compounds in the dry state andadding a small amount of water to the mixture, em-

water'to the reaction product to convert any un reacted titaniumtetrachloride to titanium oxy' chloride.

- 8; A method tor producing a dry solid aqueous- WILLIAM L. BILLS.

REFERENCES CITED The following references are of record'in the fileofthis patent: UNITED STATES PATENTS Number Name Date 723,088 'Warr Mar.17, 1903. 2,395,922 Timmons Mar. 5, 1946 2,416,447 Laughlin et al. Feb.25, 1947 2,427,997 White Sept. 23,194 2,461,302 Truhlar et a1. Feb. 8,1949 2,570,566

Lane et a l 001?. 9, 1951 OTHER REFERENCES 7 Industrial and EngineeringChemistry, Vol. 42, No.13, Mar. 1950, pgs. 440-444, vby Gulledge andSeidel. Ephraim: Inorganic Chemistry, Nordeman Pub. Co., Inc., N. Y.,1943, pgs. 747 and 755-756.

2. DRY, POWDERY FLAME-RETARDING COMPOSITION, USEFUL FOR THE TREATMENT OFINFLAMMABLE TEXTILE MATERIALS AND SOLUBLE IN AN AQUEOUS SYSTEM, WHICHCONSISTS IN TITANIUM OXYCHLORIDE AND ANTIMONY CHLORIDE, THE ATOM RATIOOF ANTIMONY TO TITANIUM IN SAID COMPOSITION BEING NOT MORE THAN TWO ANDNOT LESS THAN ONE-HALF.